1. Field of Invention
The present invention relates to a coupled torsion beam axle (CTBA) suspension which is one type of a suspension of a vehicle, and more particularly, to a CTBA with improved compliance characteristics that can control a toe value of a rear wheel in steering to be toed in during the steering with a simple structure.
2. Description of Related Art
A coupled torsion beam axle (CTBA) which is one type of a suspension of a vehicle has the small number of components, has excellent durability, and is easily serviced due to a simple structure and relatively more inexpensive than other suspension devices, and as a result, the CTBA is adopted primarily in a small-sized vehicle.
Referring to a substantial structure of the CTBA suspension mechanism, as shown in FIGS. 1 and 2, the CTBA includes a torsion beam 111, trailing arms 112 provided at both ends of torsion beam 111, and carriers 113 on which rear wheels RWs are mounted provided in trailing arms 112, respectively.
However, CTBA 100 has a structural characteristic in that rear wheels RWs are toed out when the vehicle turns round. Therefore, a rear wheel steering device may be provided in the CTBA as disclosed in a prior art document of KR 10-2006-0006796 in order to improve handling and driving stability. As shown in FIG. 1, when a side force Fs acts while the vehicle turns round, rear wheel RW receiving side force Fs is toed out in direction A as shown in FIG. 1 or when an outer wheel of rear wheel RW bumps (B) and thus an inner wheel rebounds (R), a toe value of rear wheel RW is toed out to damage steering stability. Therefore, the toe value of rear wheel RW needs to be controlled by using an actuator and a link member.
That is, the actuator and the link member that can control the toe value of the rear wheel are provided in the CTBA and a controller actuates the actuator according to a driving condition to control the toe value of the rear wheel.
However, as described above, since the technology that controls the toe value of the rear wheel through electronic control is expensive, the manufacturing cost of the vehicle is increased and a configuration is complicated.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.